Give one reason for the following statements :
(a) Muscles are able to contract and relax to bring about movements.
(b) Muscles of heart are called involuntary muscles.
- Muscles are special fibres in the body that contract and relax to cause movements. Movement is caused by the contraction and relaxation of muscles. When one muscle contracts, the other relaxes and this causes displacement.
- The muscles of our heart are called involuntary muscles as they don't work according to our will.